Gas burners

ABSTRACT

A gas burner has a hollow cylindrical body and a cap having holes or a slit. The burner is fed with combustible gas through an intake. The holes or slit form nozzles for jets of this gas which produce a flame disposed as a fan. Guard plates may be used to protect the flame from the sides. The flame is fed only with secondary combustion air.

nited States Patent [72] Inventor Aldo Polidoro Via Rosmini, 10, Schio, Vicenza, Italy [21] App]. No. 854,952 22 Filed Sept. 3, 1969 [45] Patented Nov. 2,1971 [32] Priorities Sept. 7, 1968 33 Italy 31 61625 A/68;

June 21, 1969, Italy, No. 61592 A/69 [54] GAS BURNERS [56] Rellerences Cited UNITED STATES PATENTS 3,204,684 9/1965 Reed 431/349 3,439,997 4/1969 Hancock et a] 431/350 FOREIGN PATENTS 1,133,705 11/1968 Great Britain 431/350 Primary ExaminerCarroll B. Dority, Jr. Attorney-Richards & Geier ABSTRACT: A gas burner has a hollow cylindrical body and a cap having holes or a slit. The burner is fed with combustible gas through an intake. The holes or slit form nozzles for jets of this gas which produce a flame disposed as a fan. Guard plates may be used to protect the flame from the sides. The flame is fed only with secondary combustion air.

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ENTOR: A oldoro INV mJwLMAA-LU ATTORNESS GAS BURNERS This invention relates to gas burners.

Many gas burners known in prior art operate on the socalled Bunsen principle in which the gas, before burning, is mixed with primary combustion air in a mixing chamber, the mixture then being made to flow out of nozzles outside of which it is mixed with secondary combustion air and ignited, giving rise to a flame substantially composed of three parts, which are called internal, central and external flame sections, respectively.

Such burners always make a certain amount of noise due to the formation of small quantities of a noisy mixture within the internal flame, and this noise may in certain cases, such as, for example, in some devices for domestic use, be objectionable.

Furthermore, there may be a disadvantage due to the fact that the primary combustion air may contain dust which may partially block the inlet and/or outlet of the mixing chamber.

An object of the present invention is to eliminate the drawbacks of prior art constructions.

Other objects of the present invention will become apparent in the course of the following specification.

In the accomplishment of the objectives of the present invention it was found desirable to provide a gas burner in which the gas burns in a fan-shaped flame emerging from a series or nozzles or a slit disposed on an arc of a circle; the flame may be protected by flameproof plates arranged at the sides of the nozzles, producing practically silent combustion. The burner has a high thermal output, with flame jets of relatively short length and dart-shaped.

In some constructions of burners of the present invention, the main flame is formed by a fan of long thin darts in which the inner and center sectors are practically eliminated, only the outer section remaining, which gives rise to perfectly regular and uniform combustion, thus greatly reducing the noise and eliminating any possibility of blocking an inner chamber of the burner, since it is not fed with primary combustion air.

In order to obtain such a result, it is necessary to provide nozzles of relatively small cross section spaced apart from each other so that adjacent darts slightly overlap each other while remaining quite distinct.

The protective plates are swept by the darts which heat them and produce an increase in the speed of combustion of the gas, with improved regularity of combustion.

In another embodiment of the present invention combustion air intake holes are provided at the base of the protective plates, thus producing an even better effect.

.Since the burner of the present invention may be fed with gas supplies having different combustion speeds and with varying pressures, difficulties may occur in igniting the burner; such ignition can take place only at the base of the individual darts of flame, particularly for gases having a low ignition speed, as for example, methane.

This is overcome by the provision of lateral nozzles of smaller cross section which send jets of gas against an obstacle, formed by wire meshing having the form of a channel or tube, or by deformation of the lateral protection plates, thus providing a much slower flame but one which is more stable; ignition of the burner is produced by applying an external flame to the sides of the burner.

This arrangement also makes it possible to produce aligned burners so that ignition can be easily transferred from one burner to another.

The fan of flames may have a form different from that of a sector of a circle, by providing holes of different diameters.

In another embodiment of the invention the body of the burner is provided with a single straight slit through which a combustible gas issues to feed the flame which is protected by two lateral plates.

The central body of the burner may have a head of ceramic material provided with a central slot through which the combustible gas flows out.

In yet another embodiment of the invention the gas feeding a pilot flame is caused to flow through a pressure-reducing hole so as to make the pilot flame more stable. For this purpose the holes for the pilot flames are preceded by an annular conduit fed with gas issuing from the main body of the burner through holes of small cross section which reduce the pressure of the gas in the conduit.

There may be three pilot flames on each side of the burner fed with gas at a low pressure from the auxiliary conduit, thus ensuring not only good stability of the flame but also preheating of the combustion air flowing along the inner walls of the guard plates which feeds the main flame.

The entire cylindrical body of the burner may be surrounded by an annular slit from which a film of pilot flames issues, fed with low-pressure gas coming from an auxiliary conduit, thus ensuring the stability of the flame, without the necessity of guard plates which in this case are replaced by the pilot flame.

The invention will appear more clearly from the following detailed description when taken in connection with the accompanying drawings showing, by way of example only, preferred embodiments of the inventive idea.

In the drawings:

FIG. 1 is a section through a gas burner constructed in accordance with the principles of the present invention;

FIG. 2 is a side view of the burner shown in FIG. 1;

FIG. 3 is a plan view of the burner shown in FIG. 1;

FIG. 4 is a section through a second embodiment of the burner of the present invention;

FIG. 5 is a side view of the burner shown in FIG. 4;

FIG. 6 is a plan view of the burner shown in FIG. 4;

FIG. 7 is a section through a third embodiment of the burner of the present invention;

FIG. 8 is a side view of the burner shown in FIG. 7;

FIG. 9 is a plan view of the burner shown in FIG. 7;

FIG. 10 is a front view of a fourth embodiment of the burner of the present invention;

FIG. 11 is a side view of the burner shown in FIG. 10;

FIG. 12 is a front view, partly in section, of a fifth embodiment of the burner of the present invention;

FIG. 13 is a side view of the burner shown in FIG. 12;

FIG. 14 is a front view showing a plurality of aligned burners;

FIG. 15 is a section through a sixth embodiment of the burner of the present invention;

FIG. 16 is a side view of the burner shown in FIG. 15;

FIG. 17 is a plan view of the burner shown in FIG. 15;

FIG. 18 is a section through a seventh embodiment of the burner of the present invention;

FIG. 19 is a side view, partly in section, of the burner shown in FIG. 18;

FIG. 20 is a plan view of the burner shown in FIG. 18;

FIG. 21 is a section through an eighth embodiment of the burner of the present invention;

FIG. 22 is a transverse section through the burner shown in FIG. 21;

FIG. 23 is a plan view of the burner shown in FIG. 21;

FIG. 24 is a section through a ninth embodiment of the burner of the present invention provided on each side with multiple holes for the pilot flames;

FIG. 25 is a side view of the burner shown in FIG. 24;

FIG. 26 is a plan view of the burner shown in FIG. 24;

FIG. 27 is a section through a tenth embodiment of the burner of the present invention having an annular pilot flame;

FIG. 28 is a side view of the burner shown in FIG. 27;

FIG. 29 is a plan view of the burner shown in FIG. 27.

FIGS. 1, 2 and 3 show the first embodiment of the burner of the present invention, which comprises a cylindrical body I, internally hollow and connected by a threaded frustoconical extension 2 to the main gas pipe.

The cylindrical body 1 is closed at the top by a spherical cap 3 in which the nozzles 4 are disposed in an arc of a circle of limited extent. The jets of gas which produce the main flame darts flow out through the nozzles. At the side of the nozzles and at a certain distance therefrom, are two smaller bores 5 through which the pilot jets of gas flow. These jets impinge on gridlike parts or baffles 6, slowing down the speed of the gas as it flows out, thus ensuring greater stability of the flames and also making possible ignition of the burner from the sides.

The grids 6 are secured to two sideplates 7 which act as guards and extend in an arc of a circle with extensions parallel to the fan of flames issuing from the nozzles 4; the plates are connected to a collar 13.

A grid 8, disposed near the bottom of the hollow cylindrical body 1, filters the combustible gas coming through the opening 2, preventing any impurities carried by the flow of gas from blocking the nozzles 4 and 5.

The nozzles 4 may have different diameters so as to vary the ensuing fan offlames.

The second embodiment of the burner, shown in FIGS. 4, and 6, differs from the burner shown in FIGS. 1, 2 and 3 merely in the different form of the side grids 9 which are tubular, a feature which gives the pilot flame a more precise orientation.

In the third embodiment of the invention shown in FIGS. 7, 8 and 9, the effect of laterally slowing down the flames issuing from the burner is attained by bending in the guard plates 7 in such manner as to restrict the space between them at the sideplate portions 10.

In this manner narrow lateral passages are formed at the sides of the burner to slow down the rate of flow of the gas of the pilot flames, thus ensuring greater stability of the flames in the entire burner.

In the fourth embodiment of the burner shown in FIGS. 10 and 11, holes 11 are formed in the base of the lateral guard plates 7 to facilitate the supply of combustion air to the base of flame darts.

This is particularly suitable for burners intended for gas having a low ignition speed, such as methane.

Other variants may be provided such as for example, the closure of the lower end of frustoconical socket 2, the bottom being provided with a hole 12 of relatively small diameter, for the passage of the gas, as shown in the fifth embodiment illustrated in FIGS. 12 and 13.

In this manner a limitation of the pressure within the cylindrical body 1 ofthe burner is obtained.

It may be also possible to make the guard plates of wire meshing or of sheet metal, the two sideplates being connected together by a hood, also of wire meshing, slipped on the cylindrical body ofthe burner.

FIG. 14 shows an alignment of burners illustrating how the flames can be easily propagated from one burner to the next because the lateral flame darts overlap each other, thus permitting rapid ignition of the entire row of burners, starting from one end.

Several rows of burners may be arranged to provide a complex ofburners disposed over a plane area, thus concentrating the generation of a considerable quantity of heat into a small area.

In the sixth embodiment of the invention, shown in FIGS. 15, 16 and 17, the burner comprises a cylindrical body 15, provided at the bottom with a frustoconical intake 16 for the gas, and, at the top, with a closure member 17 having the form of a spherical cap in which a long narrow slit 18 is formed through which the gas flows out.

Holes 19, disposed laterally of the extension of the slit l8, feed the pilot flames.

The sideplates 20 which extend parallel to the flame enable the flame itself to be fed with very hot air, since the air flows over the plates and is heated thereby. This causes an increase in the speed of propagation of the flame and improves the stability thereof, since the speed of propagation of the flame in an air and gas fuel mixture is greater the higher the temperature.

In the seventh embodiment of the invention shown in FIGS. 18, 19 and 20, the body 21 ofthe burner is provided with a ceramic top member 22 in the end of which a slit 23 is formed beneath which a perpendicular groove 24 is provided.

Through the slit 23 the gas feeds a flame in the form of a fan, protected by the sideplates 25, similarly to the embodiments described above. I

In this latter case the flame is not provided with pilot flames,

since the stability, obtained by means of guard plates, is adequate.

In the eighth embodiment of the invention illustrated in FIGS. 21, 22 and 23, the pilot flames issuing from the holes 26 are fed with gas from an annular conduit 27 formed by the gap between the outer collar 28 and the head 29 of the burner, the gas flowing into the conduit through pressure reduction holes 30 from the main body of the burner.

In this manner the gas flows out through the holes 26 at a reduced pressure relative to that with which the main body of the burner is fed, thus giving the pilot flames high stability, since the outflow speed of the gases is less than the speed of propagation of the flames even at low temperature.

In the ninth embodiment of the invention, shown in FIGS. 24, 25 and 26, there are three holes for the pilot flames on each side of the burner, Le. a hole 31 formed in the outer vertical wall of the annular chamber 32, which surrounds the head of the burner, a hole 33 pointing towards the edge of an upper annular projection formed in the same inner wall and a lateral hole 34, formed in said projection, but in the proximity of one of the guard plates 35, along the inner surface ofwhich the combustion air flows which is thus heated before feeding the principal flame of the burner.

In a final tenth embodiment of the invention, shown in FIGS. 27, 28 and 29, the principal body of the burner 37 is completely surrounded by a collar 38 which, together therewith, forms an annular slit 39 through which the gas from the annular chamber 40 flows out; here the gas is at a reduced pressure, since it flows in through holes 41 of small diameter, producing a film of pilot flames over the entire circumference of the body ofthe burner.

In this embodiment of the invention the vertical guard plates are not necessary, since they are replaced by the film of pilot flames issuing from the annular slit 39.

I claim:

I. A gas burner comprising a hollow cylindrical body having a lower frustoconical extension and a top spherical closure cap, a cylindrical member surrounding said body and engaging it adjacent said extension and said cap, said cylindrical body having an opening communicating with said chamber, whereby an annular chamber is formed surrounding said body, said cap having a series ofsmall holes disposed along an are on the cap and constituting outlet nozzles for jets of gas to produce darts of flame forming a fan-shaped flame, two guard plates, each of said guard plates having an upper circular edge extending above said cap, a spherical section extending around said cap and engaging said body and a lower portion, the two lower portions of the guard plates extending on opposite sides of said body and having substantially horizontal portions extending toward each other and lowermost portions which engage each other, said cylindrical member having at least one side hole, a hole located adjacent said cap and a hole located adjacent one of said guard plates, said holes being adapted to pass pilot flames. 

1. A gas burner comprising a hollow cylindrical body having a lower frustoconical extension and a top spherical closure cap, a cylindrical member surrounding said body and engaging it adjacent said extension and said cap, said cylindrical body having an opening communicating with said chamber, whereby an annular chamber is formed surrounding said body, said cap having a series of small holes disposed along an arc on the cap and constituting outlet nozzles for jets of gas to produce darts of flame forming a fan-shaped flame, two guard plates, each of said guard plates having an upper circular edge extending above said cap, a spherical section extending around said cap and engaging said body and a lower portion, the two lower portions of the guard plates extending on opposite sides of said body and having substantially horizontal portions extending toward each other and lowermost portions which engage each other, said cylindrical member having at least one side hole, a hole located adjacent said cap and a hole located adjacent one of said guard plates, said holes being adapted to pass pilot flames. 